If the lake was originally on a level with the valley, it would soon have formed incrustations round its edge, which every casual or permanent overflow would have tended to raise; and thus, in the course of ages, the entire hill may have been formed by a mere accumulation of petrefactions.

The formation would progress more or less rapidly according to the tendency of the lake to overflow its bounds; which tendency must have been strong until the water reached its present natural level--the level, probably, of some other sheet of water in the hills, with which it is connected by an underground siphon.

The lake, which is of an irregular shape, is about 300 paces in circumference.

Its water, notwithstanding the quantity of mineral matter held in solution, is exquisitely clear, and not unpleasing to the taste.

Formerly it was believed by the natives to be unfathomable; but experiments made in 1837 showed the depth to be no more than 156 feet.
The ruins which at present occupy this remarkable site consist of a strong wall, guarded by numerous bastions and pierced by four gateways, which runs round the brow of the hill in a slightly irregular ellipse, of some interesting remains of buildings within this walled space, and of a few insignificant traces of inferior edifices on the slope between the plain and the summit.